| Due to the significant pulse,the near-fault ground motion is the main cause of structural damage in the near-fault area,and many researchers at home and abroad have paid more and more attention to it.Because there are a large number of active faults in China,with the laying of buried gas pipelines,many buried gas pipelines built or under construction are threatened by near-fault ground motion.At present,many achievements have been made in the study of near-fault ground motion and buried gas pipeline respectively.However,there are few studies on the seismic response characteristics of the near-fault buried gas pipelines under the coexistence condition of the two.Therefore,the numerical simulation analysis method was used to study the seismic response characteristics of the near-fault buried gas pipeline,the targeted seismic measures were proposed and verified,and suggestions for seismic measures of near-fault buried gas pipeline projects were made.The main research contents are as follows.(1)According to four typical models of the dynamic interaction between soil and pipeline,the theoretical basis,advantages and disadvantages of the dynamic interaction between soil and buried pipeline was systematically summarized,and the applicable pipe-soil interaction model was selected.(2)The seismic response characteristics of the buried gas pipeline under the near-fault pulse-like ground motion were studied by the finite difference software FLAC3D.Based on the variation of shear stress and relative displacement of pipe-soil along the axis of pipeline,the potential damage location of pipeline was determined,and the law that the shear stress of the pipeline and relative displacement of pipeline and soil were symmetrically distributed along the pipeline axis direction was obtained.(3)The influence of buried depth,diameter,thickness of pipeline,site soil,loading mode and type of seismic wave,peak ground motion acceleration and presence or absence of joints on seismic response characteristics of buried gas pipelines near faults were analyzed by using control variable method.The significance degree of each influencing factor was quantitatively evaluated by the orthogonal test design range analysis method.(4)Based on the analysis results of seismic response characteristics and influence factors of buried gas pipelines under the near-fault pulse-like ground motion obtained in this paper,and combined with the existing experience of seismic damage,the main factors that have great influence on the sesimic damage of the near-fault buried gas pipelines were summarized.On this basis,targeted seismic measures were proposed,the effectiveness of the proposed seismic measures was verified by using FLAC3D,and suggestions for seismic measures of near-fault buried gas pipeline projects were made. |
